It is currently 23 Nov 2014, 04:18
Join the free forum or login with your account and the annoying banner goes away

FishFinderMounts

All times are UTC - 5 hours [ DST ]




 Page 1 of 2 [ 22 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Jon Boat Rebuild
PostPosted: 29 Dec 2011, 17:52 

Joined: 29 Dec 2011, 17:29
Posts: 227
Hi every one, I am new to the forum and will jump right in with my project. Hopefully you guys can help me steer clear of some of the disasters I am already encountering. I have lurked here a couple of times, so now I am a member and look forward to some good tips and pointers, here goes...

Okay, I have used pressure treated lumber on my jon boat not thinking anything of it and later was warned that it would corrode the aluminum. What? I don’t believe it. Then I thought about it a little and I know that copper is the main ingredient in the treatment to prevent fungus (rot) and I though maybe it would. I love PT wood and have used it with great successes in rebuilding my fiberglass boat. So it only seemed natural to use it in my tin boat. Well I had already used it before I was warned by those that had bad experiences. I questioned the danger and I was WRONG!

I walked out and started looking over the transom of my boat. I had attached a red neck jack plate, a piece of 2x10 pt to mount the motor on to raise it up mainly. I didn’t see any corrosion around it but I did notice some spots. See picture below.
Image

What the heck? This is a hole corroded through the metal. Granted the metal is only 1/8” thick but still… This is in the area where the transom is reinforced with wood from the factory. So I pulled off my red neck jack plate and it looks like this…
Image

Okay, this isn’t good I am going to go ahead and tear into this thing and see what I have to do to correct this problem. The transom is bolted, riveted and welded together for crying out loud.
Image

After looking it over I decide the only way to do this is from the top so I need to cut the weld…
Image

Piece of cake, was easier than I thought using the skill saw and carefully working it backwards…
Image

Image

Oh yea, some pop rivets too…
Image

The cap is off, yep, PT plywood…
Image

So here is the inside aluminum cover piece…
Image

The wood is in great shape, yea! But, I am going to throw it out now!


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 29 Dec 2011, 17:53 

Joined: 29 Dec 2011, 17:29
Posts: 227
Okay, so now I have some questions. What is the best thing to clean up this aluminum with?

I know there are holes in it but I don’t really care since they are all well above the water line. What I am thinking of doing is replacing the wood with a structural foam core material and then using some bed liner type stuff (not sure what yet) to basically glue the core material back to the transom where the wood was and then reassembling the thing back the way it was. I am thinking that some of the bed liner material will act as a glue and sealant and will help to restore the integrity of the transom. The liner stuff will not be seen since it will be under the core material and then the aluminum cover.


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 29 Dec 2011, 23:19 
User avatar

Joined: 15 Sep 2011, 08:48
Posts: 1913
Location: N.E. SC coast
Use a stainless steel wire brush, or a SS wire wheel for an angle grinder (you'll probably have to order it from somewhere like Grainger or McMaster-Carr, as places like Lowes or Home Depot do not carry items like this) Use the brush or the wire wheel to remove as much oxidation as possible.

Once you have the oxidation removed, use phosphoric acid (Ospho) to etch off any remaining crud, then a rinse with some baking soda and then a final rinse with water. This will neutralize the oxidation process a good bit.

If you decide to repair the corrosion holes, there are a couple of ways to do it. You could use 5200. You can also use a product called "Ce-Ram-Grout" It's a 2 part ceramic grout that is used to repair corrosion on metal storage tanks, and on boat hulls. Also, there's a type of zinc-based solder that some people here have used to seal rivets (I forget what it's called)



_________________
ALUMA-JET project:
viewtopic.php?f=21&t=22023


Fishing, jet skiing, target shooting, jet-boating, and even a little oyster harvesting with Larry The Cable Guy.
Watch it all right here:

http://www.youtube.com/user/HKPSG1Shooter?feature=mhee
Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 30 Dec 2011, 08:46 

Joined: 29 Dec 2011, 17:29
Posts: 227
Thanks, instead of phosphoric acid what about muriatic acid, I have some of that.


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 30 Dec 2011, 19:27 
User avatar

Joined: 15 Sep 2011, 08:48
Posts: 1913
Location: N.E. SC coast
Definitely NOT. Muriatic acid will probably dissolve the aluminum into alka-selzer.

Phosphoric acid is the active ingredient used in aluminum mag wheel cleaner, as it is designed to etch and clean aluminum without damaging it as other acids will do.



_________________
ALUMA-JET project:
viewtopic.php?f=21&t=22023


Fishing, jet skiing, target shooting, jet-boating, and even a little oyster harvesting with Larry The Cable Guy.
Watch it all right here:

http://www.youtube.com/user/HKPSG1Shooter?feature=mhee
Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 03 Jan 2012, 12:22 

Joined: 29 Dec 2011, 17:29
Posts: 227
Thanks, I asked that question of the supplier and he said it could potentially catch fire as well, he said definitely use the phosphoric acid. Looks like I will be using a product called Nida (sp) core which is a reinforced structural foam board. It costs the same or less than maring ply and I won’t have to epoxy coat it to protect it from rotting. I will be epoxy-ing it together though. I am also thinking of epoxy-ing the nida core to the transom skin as well, this will fix the holes and add more stiffness.


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 03 Jan 2012, 17:10 

Joined: 29 Dec 2011, 17:29
Posts: 227
Okay, been doing a little more research on the Nida-core panels since I wasn’t too familiar with it and found out it is a honey comb material, I think it will work great for the transom but not too sure about the decking. I just want to be able to screw it down and I am afraid the screws might just pull through. Don’t really want to put big fender washers down either. Now I am back to looking at Marine Ply and epoxy, more than I wanted to do. Will keep researching.

Anyone on this sight familiar with Nida-core?


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 04 Jan 2012, 17:05 

Joined: 29 Dec 2011, 17:29
Posts: 227
Well after further discussion with the folks that sell the nida-core board I talked to a different gentleman this time and he said the nida-core won’t work for what I want to do. In the transom he said it could and probably will crush from the motor clamps and torque of the motor. There is an aluminum skin and it may work but, it may not.

He recommended a denser foam core board that is designed for transoms. It is very expensive and not worth it for this project. The nida-core board is basically a coring material for decking and hulls and such where the load is spread out more. I could use it for the decking but you can’t screw it down since the screw will just pass through it, I would need to make a plug which I could do and it still needs to be glassed over, might as well use good old plywood.

Looks like I am right back where I started, oh well.


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 04 Jan 2012, 18:27 

Joined: 29 Dec 2011, 17:29
Posts: 227
Next question...

If I coat the original PT Plywood from the transom with epoxy will it seal the copper and protect the aluminum from reacting with it? Has anyone tried this before??

Thanks.


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 04 Jan 2012, 19:37 

Joined: 05 Oct 2008, 12:14
Posts: 2644
Location: Algonquin Il
Just use exterior grade plywood.



_________________
1971 14' Ward's Sea King Jon Boat / 1983 Mariner 25HP
Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 05 Jan 2012, 08:40 

Joined: 29 Dec 2011, 17:29
Posts: 227
Yea I know but I already have these pieces cut and fit and there is nothing wrong with them other than they were soaked at one time in a copper ion solution, eerrrr. I was hoping someone out there had tried this and it worked. Maybe I should be the first? It seems that if the copper is sealed up in the wood then it won't be able to get at the aluminum. But at this point it is a guess. I suppose I could try an experiment but corrosion is such a slow process.


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 05 Jan 2012, 14:51 
User avatar

Joined: 12 Apr 2010, 08:50
Posts: 1140
Location: West TN
lckstckn2smknbrls wrote:
Just use exterior grade plywood.


X2



_________________
1986 Landau 1470F
1973 PolarKraft 1440 MV
1966 Johnson 20 HP
Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 09 Jan 2012, 09:08 

Joined: 29 Dec 2011, 17:29
Posts: 227
Here is what I have decided to do. I have found out that there is a kiln dried pressure treated plywood that uses the old style treatment (prior to 2003). It is also a marine grade wood and is used by some plastic boat manufacturers in boat building. Let’s face it wood is pretty good stuff it if wasn’t for the fact that it will rot, eliminate that and you have a product that is almost unbeatable when you compare all aspects including value.

The problem with the treatment is that it is not friendly to metal like aluminum (we already know that) but, if you use a barrier you can reduce or eliminate the problem. It is also used by pontoon boat builders. They use it for decking without any kind of sealer and they claim it won’t hurt aluminum but, they do isolate it from the aluminum with some sort of barrier material, and that is what I am going to do.

Basically, I am going to do what I originally proposed doing. I will use the original wood since it is the old style treatment, I will seal it and then bed it in gflex epoxy for the transom. For the decking, again I will use the wood I used before since it is still good and seal it with the epoxy, although I will not glue it to the stringers I will use something else as a barrier, I haven’t figured that one out yet. I will keep posting my progress for those that are interested or for those that want to call me an idiot. :D

By bedding the transom wood in the gflex epoxy I will accomplish to things, one it will isolate the wood from the aluminum and two it will prevent water from being trapped between the wood and the aluminum, another potential for corrosion no matter what the material is.


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 09 Jan 2012, 16:37 

Joined: 26 Dec 2011, 02:27
Posts: 24
Location: Marysville, California
One thing that could help with your corrosion after you get all that stuff cleaned off your aluminum is to get a good self-etching primer and get a nice good coat of that on there. That will help out with protecting from corrosion im sure. Make sure you clean the aluminum really good with some rubbing alcohol and let it dry before you put the primer on if you go in that direction anyway.


Offline
 Profile  
 
 Post subject: Jon Boat Rebuild
PostPosted: 09 Jan 2012, 18:01 

Joined: 29 Dec 2011, 17:29
Posts: 227
Right on r49, surface prep is the most important thing to applying any kind of coating. I am not sure however that I will need or want to apply a primer for the epoxy, I will see what the manufacturer recommends. Aluminum can be tricky stuff.


Offline
 Profile  
 
Display posts from previous:  Sort by  
 Page 1 of 2 [ 22 posts ]  Go to page 1, 2  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: Exabot [Bot], Google Adsense [Bot] and 17 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Join the free forum or login with your account and the annoying banner goes away

Xtremeboats